<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>数学表达式</title>
    <script type="text/javascript">
        function calcF(x) {
            var result;
            result = 4 * x * x + 3 * x + 2;
            window.alert("结果" + result);
        }
    </script>
</head>
<body>
    <input type="button" value="输入" onclick="calcF(prompt('请输入'))">
</body>
</html>